OGL: Support full-resolution frame dumping

Source/Core/VideoBackends/OGL/PostProcessing.cpp

@@ -44,8 +44,6 @@ void OpenGLPostProcessing::BlitFromTexture(TargetRectangle src, TargetRectangle
 {
   ApplyShader();
 
-  glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
-
   glViewport(dst.left, dst.bottom, dst.GetWidth(), dst.GetHeight());
 
   OpenGL_BindAttributelessVAO();

Source/Core/VideoBackends/OGL/Render.cpp

@@ -768,8 +768,7 @@ Renderer::~Renderer()
 {
   FlushFrameDump();
   FinishFrameData();
-  if (m_frame_dumping_pbo[0])
-    glDeleteBuffers(2, m_frame_dumping_pbo.data());
+  DestroyFrameDumpResources();
 }
 
 void Renderer::Shutdown()
@@ -1380,11 +1379,30 @@ void Renderer::SwapImpl(u32 xfbAddr, u32 fbWidth, u32 fbStride, u32 fbHeight,
   std::swap(flipped_trc.top, flipped_trc.bottom);
 
   // Copy the framebuffer to screen.
+  glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
   DrawFrame(flipped_trc, rc, xfbAddr, xfbSourceList, xfbCount, fbWidth, fbStride, fbHeight);
 
-  glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
-
-  DumpFrame(flipped_trc, ticks);
+  // The FlushFrameDump call here is necessary even after frame dumping is stopped.
+  // If left out, screenshots are "one frame" behind, as an extra frame is dumped and buffered.
+  FlushFrameDump();
+  if (IsFrameDumping())
+  {
+    // Currently, we only use the off-screen buffer as a frame dump source if full-resolution
+    // frame dumping is enabled, saving the need for an extra copy. In the future, this could
+    // be extended to be used for surfaceless contexts as well.
+    bool use_offscreen_buffer = g_ActiveConfig.bInternalResolutionFrameDumps;
+    if (use_offscreen_buffer)
+    {
+      // DumpFrameUsingFBO resets GL_FRAMEBUFFER, so change back to the window for drawing OSD.
+      DumpFrameUsingFBO(rc, xfbAddr, xfbSourceList, xfbCount, fbWidth, fbStride, fbHeight, ticks);
+      glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
+    }
+    else
+    {
+      glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
+      DumpFrame(flipped_trc, ticks);
+    }
+  }
 
   // Finish up the current frame, print some stats
 
@@ -1630,9 +1648,6 @@ void Renderer::FlushFrameDump()
 
 void Renderer::DumpFrame(const TargetRectangle& flipped_trc, u64 ticks)
 {
-  if (!IsFrameDumping())
-    return;
-
   if (!m_frame_dumping_pbo[0])
   {
     glGenBuffers(2, m_frame_dumping_pbo.data());
@@ -1669,6 +1684,82 @@ void Renderer::DumpFrame(const TargetRectangle& flipped_trc, u64 ticks)
   glBindBuffer(GL_PIXEL_PACK_BUFFER, 0);
 }
 
+void Renderer::DumpFrameUsingFBO(const EFBRectangle& source_rc, u32 xfb_addr,
+                                 const XFBSourceBase* const* xfb_sources, u32 xfb_count,
+                                 u32 fb_width, u32 fb_stride, u32 fb_height, u64 ticks)
+{
+  // This needs to be converted to the GL bottom-up window coordinate system.
+  TargetRectangle render_rc = CalculateFrameDumpDrawRectangle();
+  std::swap(render_rc.top, render_rc.bottom);
+
+  // Ensure the render texture meets the size requirements of the draw area.
+  u32 render_width = static_cast<u32>(render_rc.GetWidth());
+  u32 render_height = static_cast<u32>(render_rc.GetHeight());
+  PrepareFrameDumpRenderTexture(render_width, render_height);
+
+  // Ensure the alpha channel of the render texture is blank. The frame dump backend expects
+  // that the alpha is set to 1.0 for all pixels.
+  FramebufferManager::SetFramebuffer(m_frame_dump_render_framebuffer);
+  glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
+  glClear(GL_COLOR_BUFFER_BIT);
+
+  // Render the frame into the frame dump render texture. Disable alpha writes in case the
+  // post-processing shader writes a non-1.0 value.
+  glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_FALSE);
+  DrawFrame(render_rc, source_rc, xfb_addr, xfb_sources, xfb_count, fb_width, fb_stride, fb_height);
+
+  // Copy frame to output buffer. This assumes that GL_FRAMEBUFFER has been set.
+  DumpFrame(render_rc, ticks);
+
+  // Restore state after drawing. This isn't the game state, it's the state set by ResetAPIState.
+  glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
+  FramebufferManager::SetFramebuffer(0);
+}
+
+void Renderer::PrepareFrameDumpRenderTexture(u32 width, u32 height)
+{
+  // Ensure framebuffer exists (we lazily allocate it in case frame dumping isn't used).
+  // Or, resize texture if it isn't large enough to accommodate the current frame.
+  if (m_frame_dump_render_texture != 0 && m_frame_dump_render_framebuffer != 0 &&
+      m_frame_dump_render_texture_width >= width && m_frame_dump_render_texture_height >= height)
+  {
+    return;
+  }
+
+  // Recreate texture objects.
+  if (m_frame_dump_render_texture != 0)
+    glDeleteTextures(1, &m_frame_dump_render_texture);
+  if (m_frame_dump_render_framebuffer != 0)
+    glDeleteFramebuffers(1, &m_frame_dump_render_framebuffer);
+
+  glGenTextures(1, &m_frame_dump_render_texture);
+  glActiveTexture(GL_TEXTURE9);
+  glBindTexture(GL_TEXTURE_2D, m_frame_dump_render_texture);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 0);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+  glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
+
+  glGenFramebuffers(1, &m_frame_dump_render_framebuffer);
+  FramebufferManager::SetFramebuffer(m_frame_dump_render_framebuffer);
+  FramebufferManager::FramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
+                                         m_frame_dump_render_texture, 0);
+
+  m_frame_dump_render_texture_width = width;
+  m_frame_dump_render_texture_height = height;
+  TextureCache::SetStage();
+}
+
+void Renderer::DestroyFrameDumpResources()
+{
+  if (m_frame_dump_render_framebuffer)
+    glDeleteFramebuffers(1, &m_frame_dump_render_framebuffer);
+  if (m_frame_dump_render_texture)
+    glDeleteTextures(1, &m_frame_dump_render_texture);
+  if (m_frame_dumping_pbo[0])
+    glDeleteBuffers(2, m_frame_dumping_pbo.data());
+}
+
 // ALWAYS call RestoreAPIState for each ResetAPIState call you're doing
 void Renderer::ResetAPIState()
 {

Source/Core/VideoBackends/OGL/Render.h

@@ -128,6 +128,17 @@ private:
 
   void FlushFrameDump();
   void DumpFrame(const TargetRectangle& flipped_trc, u64 ticks);
+  void DumpFrameUsingFBO(const EFBRectangle& source_rc, u32 xfb_addr,
+                         const XFBSourceBase* const* xfb_sources, u32 xfb_count, u32 fb_width,
+                         u32 fb_stride, u32 fb_height, u64 ticks);
+
+  // Frame dumping framebuffer, we render to this, then read it back
+  void PrepareFrameDumpRenderTexture(u32 width, u32 height);
+  void DestroyFrameDumpResources();
+  GLuint m_frame_dump_render_texture = 0;
+  GLuint m_frame_dump_render_framebuffer = 0;
+  u32 m_frame_dump_render_texture_width = 0;
+  u32 m_frame_dump_render_texture_height = 0;
 
   // avi dumping state to delay one frame
   std::array<u32, 2> m_frame_dumping_pbo = {};

Source/Core/VideoBackends/OGL/main.cpp

@@ -104,7 +104,7 @@ void VideoBackend::InitBackendInfo()
   g_Config.backend_info.bSupportsSSAA = true;
   g_Config.backend_info.bSupportsReversedDepthRange = true;
   g_Config.backend_info.bSupportsMultithreading = false;
-  g_Config.backend_info.bSupportsInternalResolutionFrameDumps = false;
+  g_Config.backend_info.bSupportsInternalResolutionFrameDumps = true;
 
   // Overwritten in Render.cpp later
   g_Config.backend_info.bSupportsDualSourceBlend = true;